Phase formation control in plasma sprayed alumina-chromia coatings.
| Autor: | Dubský, Jiří |
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| Další autoři: |
Chráska, Pavel, 1943-
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| Jazyk: | angličtina |
| Předmět: | |
| Druh dokumentu: | Non-fiction |
| ISSN: | 0862-5468 |
| Abstrakt: | Abstract: Alumina is an inexpensive material often used as feedstock for plasma spraying. Hard corundum (α-Al₂O₃) is desirable in coatings, but other phases, unstable at elevated temperatures, also form as result of the complexity of the spraying processes. When chromia (Cr₂O₃) is added to Al₂O₃ a complex corundum type α-(Al,Cr)₂O₃ phase forms in the deposits. Two types of Al₂O₃/Cr₂O₃ powder feedstock with 2%, 8%, 33% and 50% Cr₂O₃ were sprayed: fused materials and mixtures of Al₂O₃ and Cr₂O₃ powders. Coatings were made by the water-stabilized plasma (WSP®) system and by commercial atmospheric plasma spraying (APS) and compared by various characterization techniques, including X-ray diffraction, scanning electron microscopy and microanalysis. Coatings made from fused feedstock by both spraying methods contain the corundum phase with its fraction increasing with increasing Cr₂O₃ content. In case of mixed feedstock the stabilization effect was observed for WSP® spraying only. Explanation of this finding is offered on basis of differences in the spraying technologies, in particular the spraying temperature. |
| Databáze: | Katalog Knihovny AV ČR |
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